Fixed

The reference curve. Every rung commits the same size, so the ladder is a straight line in capital and the worst case is arithmetic you can do in your head: levels × grid size. Fixed is not the timid choice — it is the choice that makes every other decision (levels, spread, target, leverage) legible, because nothing else is moving underneath them.

Size at level i is exactly one base lot. Rung prices step arithmetically off the base by the spread, each fill gets one take-profit one target away, and a completed cycle re-arms the same rung at the same size. There is no state to reason about beyond which rungs are filled.

Below is the wizard's own ladder table and the trading terminal's chart engine, both driven by buildLadderPlan for this mode. Change the level count, spread or target and the rung prices, sizes, capital ramp and chart lines recompute exactly as they would in the grid designer.

Cost is exactly linear in depth, so doubling the levels doubles the commitment and the coverage. This is the only family where capital planning needs no model: reserve levels × grid size ÷ leverage and you are funded for the full ladder.

Read the cost vs 5 levels column as the escalation test. A flat ladder doubles when the depth doubles; anything materially above that is a curve whose coverage has to be bought rather than simply configured.

With every rung filled, the volume-weighted average entry is 94.50 against a base of 100 and a deepest rung of 90.00 — so the average sits 55% of the way down the covered range. Getting back to flat from the bottom therefore needs a 5.00% bounce, against 5.00% for a flat ladder of the same depth — effectively identical.

Every rung is identical, so the average entry is the plain arithmetic mean of the filled levels and the bounce needed to break even is roughly half the distance travelled. Deep ladders stay affordable, which is why fixed is the only growth-free mode that is genuinely usable at forty or a hundred levels.

The last row is the metric that separates modes. Profit for a full cycle is the target percentage of deployed capital in every mode, so it cannot discriminate. What differs is how much capital has to sit reserved to earn one shallow cycle: this mode reserves 10.0× base to collect 10.0 bps of it when the first rung completes.

Ranging and mean-reverting markets, where the value comes from repetition rather than from averaging down. Fixed also fits any instrument you are metering for the first time: it isolates whether your spread and target survive the instrument's fee and volatility profile, without a size curve flattering the result.

Every rung of the ladder uses the same lot size. Capital usage is perfectly linear and knowable up front, so it is impossible to blow up from position scaling. Recovery from drawdown is the slowest of all modes because deep levels do not add extra size to average down.

The risk is not sizing, it is coverage. A flat ladder that runs out of rungs stops averaging entirely and simply holds a losing position, so the failure mode is a trend that exits the covered range — not a capital spiral. Loss at any depth is proportional, never convex.

This is the product's grid backtester, not a summary of one. It fetches public candles for the instrument you pick, rebuilds the ladder anchored on the first candle of the window, then applies the engine's own fill, take-profit, refill and stop-loss rules bar by bar. The caveat block inside the panel is part of the output — read it before trusting a number.

First the arithmetic, then the market. The table below is computed from the size curves alone; the sweep underneath replays every one of those ladders over the same real candle window, with grid_mode as the only variable.

• First deployment on a new instrument, before you have data on how it actually fills.
• Ranging or sideways regimes where cycle frequency is the edge.
• Any mandate where the maximum loss has to be stated up front and defended.
• Deep ladders — 50 levels of fixed costs what 10 levels of linear martingale costs.

• You need to recover a deep drawdown quickly; flat sizing gives you no leverage over your own average entry.
• The instrument reverts violently and you want to exploit the reversion — a growth curve monetises that better.

• Tune levels and spread, not size. Coverage = levels × spread is the only lever fixed gives you over survival.
• If cycles are rare, the spread is too wide for the instrument's volatility, not the mode's fault.
• If cycles are frequent but P&L is flat, the target is too close to the fee floor.

• Track cycles per day against the instrument's realised volatility — fixed lives or dies on fill frequency.
• Watch the deepest filled level as a coverage gauge: consistently reaching the last rung means the range assumption is wrong.
• Because capital is linear, a fixed ladder is safe to extend mid-life; adding levels costs exactly one lot each.

1. 1
   Coverage exhaustion

   Price leaves the covered range and the ladder holds a full position with no rungs left. Nothing escalates, but nothing recovers either until price returns. The fix is coverage (levels × spread) or a stop, not a different size curve.
2. 2
   Fee erosion

   A target set close to round-trip fees turns a high cycle count into a slow bleed. Fixed makes this easy to spot because the per-cycle profit is identical every time; if realised P&L is flat while cycles climb, the target is the problem.

• Pairs naturally with trail modes: because every rung costs the same, shifting the window is cheap and predictable.
• Spread sets how fast the ladder consumes depth. Widening it buys coverage for the same level count at the cost of fewer fills.
• Target sets what each cycle books. Below round-trip fees plus slippage, a grid is a fee generator regardless of the size curve.
• The stop loss is the only bound on the tail. Without it, the curve's worst case is whatever the market does, not what you planned.

1. 1
   Is fixed the same as DCA fixed?

   Mathematically yes — `dca_fixed` is an alias. The distinction is framing: DCA describes accumulation you intend to hold, fixed describes a grid you intend to cycle.
2. 2
   How deep can I safely go?

   As deep as levels × grid size ÷ leverage fits inside your reserved capital with room for the position to be underwater. That is the whole calculation — there is no curve to model.

• Sizes and capital: levelMultiplier / gridModeCurve in lib/grid/gridModes.ts, mirrored from grid_modes.hpp and the Python engine's lot calculator.
• Rung and exit prices, capital ramp, init targets and the stop line: buildLadderPlan — the same builder the wizard and grid designer use.
• Backtest fills, cycles and P&L: runBacktest / runBacktestSweep over public broker candles, applying the engine's fill, exit, refill and stop rules.
• Price charts: the trading terminal's chart engine, with the ladder drawn through its own price-line API.

• 1.Grid Modes — Overview — The full taxonomy and how to choose
• 2.Basic family — What every curve in this family has in common
• 3.Capital Allocation — Sizing an account to a Fixed ladder
• 4.Stop Loss — Bounding this curve's tail
• 5.Reading the Ladder Plan — Verifying the curve before deploying
• 6.Grid Structure — Levels, init batch and base size